1) The film's explanations are not just pseudo-scientific, but anti-scientific. It would be forgivable if the film had an interesting plot, but that's also a failure.
2) The plot is banal and presented in a depressing way.
3) The film isn't scary at all.
4) The characters are stupid; only Lars and the arrogant scientist (who actually behaves like a normal scientist, unlike the protagonist) are somewhat enjoyable. The arrogant scientist is only arrogant because he's not liked by the main heroine.
5) The gimmick of disguising as "personnel" is a failure. The film heavily hints at who is infected.
6) The main heroine is as much of a scientist as Locken and Vissi are best friends. She's stupid and is horrified when the scientist decides to take the alien's DNA and exhibits similar foolishness. But she looks good, which doesn't make her a better scientist.
7) There is no logic in the plot at all, nor in the film itself.
8) Even the action in the film is terrible.
9) The Norwegians are simpletons; they react to the Americans with "Argh, American demons!". The Americans bring light, goodness, peace, friendship, and chewing gum.
Advantages:
1) The Norwegians sing a pretty good song after finding the alien.
In short, don't go. There's nothing worthwhile, except for the song.